The present invention relates to new N-substituted indoline compounds which are useful as estrogenic agents, as well as pharmaceutical compositions and methods of treatment utilizing these compounds.
Estrogen replacement therapy has been well established as the treatment of choice in women for the prevention of osteoporosis. [C. Christiansen, R. Lindsay, Estrogen, Bone Loss and Preservation, Osteoporosis International, 1, 15-21 (1990)] The problem with unopposed estrogen therapy is that proliferative effects on the uterus may occur and be associated with endometriosis and/or endometrial cancer. Although less clear, unopposed estrogen replacement therapy has been implicated in increasing the incidence of breast tumor formation. Non-steroidal antiestrogen drugs such as Tamoxifen have been used in the treatment of breast cancer. Tamoxifen has been shown to exert an estrogen-like effect on bone in humans while acting as an antagonist in uterine tissue. However, demonstration of partial agonistic effects in the uterus is of some concern. A recent antiestrogen drug, Raloxifene, Lilly""s benzothiophene, is a non-steroidal antiestrogen which appears to be more tissue selective. While possessing the ability to spare bone, it has been demonstrated to stimulate uterine growth in animal models to a lesser degree than Tamoxifen. A review on the tissue selective action of estrogen receptor modulators has recently appeared. [T. A. Grese and J. A. Dodge In xe2x80x9cAnn. Rep. in Med. Chem.xe2x80x9d J. A. Bristol, Ed. Academic Press, New York, 1996, p.181]
The use of indoles as estrogen antagonists has been reported by Von Angerer, Chemical Abstracts, Vol. 99, No. 7 (1983), Abstract No. 53886u. Also, see, J. Med. Chem. 1990, 33, 2635-2640; J. Med. Chem. 1987, 30, 131-136. Also see Ger. Offen., DE 3821148 Al 891228 and WO 96/03375.
The compounds described in the present invention possess moderate binding to the estrogen receptor (ER) and have potential use in treating osteoporosis, prostatic hypertrophy, breast cancer and endometrial cancer.
N-substituted indolines of this invention are tissue-selective estrogen agonists/antagonists useful for the treatment of diseases associated with estrogen deficiency. They include compounds of the formula: 
wherein:
R1 is H or benzyl;
R2 is H, xe2x80x94OH, or xe2x80x94Oxe2x80x94benzyl;
R3, R4, and R5 are independently selected from H, cyano, C1-C6 alkyl (straight chain or branched), trifluoromethyl, xe2x80x94OH or the C1-C12 esters (straight chain or branched) or C1-C12 alkyl ethers (straight chain or branched or cyclic) thereof, halogens, or C1-C6 halogenated ethers, preferably C1-C3 halogenated ethers, including trifluoromethyl ether and trichloromethyl ether;
R6 is H or C1-C6 alkyl;
R7 is C1-C6 alkyl;
n is 2 to 3;
Y is O or S; and
X is 
Rxe2x80x2 is selected from C1-C6 lower alkyl or the moieties: 
or a pharmaceutically acceptable salt thereof.
Among the more preferred compounds of this invention are those in which Y is O, n is 2 and R3, R4, and R5 are independently selected from H, OH or halogen. It will be understood that the number of carbons in the alkyl groups of moieties R6 and R7 may be selected independently of each other.
The invention includes acceptable salt forms formed from the addition reaction with either inorganic or organic acids. Inorganic acids such as hydrochloric acid, hydrobromic acid, hydroiodic acid, sulfuric acid, phosphoric acid, nitric acid as well as organic acids such as acetic acid, propionic acid, citric acid, maleic acid, malic acid, tartaric acid, phthalic acid, succinic acid, methanesulfonic acid, toluenesulfonic acid, napthalenesulfonic acid, camphorsulfonic acid, benzenesulfonic acid are useful. It is known that compounds possessing a basic nitrogen can be complexed with many different acids (both protic and not protic) and usually it is preferred to administer a compound of this invention in the form of an acid addition salt. Additionally, this invention includes quaternary ammonium salts of the compounds herein, which can be prepared by reacting the nucleophilic amines of the side chain with a suitably reactive alkylating agent such as an alkyl halide or benzyl halide.
The compounds of the invention are partial estrogen agonists and display high affinity for the estrogen receptor. Unlike many estrogens, however, many of these compounds do not cause increases in uterine wet weight. These compounds are antiestrogenic in the uterus and can completely antagonize the trophic effects of estrogen agonists in uterine tissue. Due to the tissue selective nature of these compounds, they are useful in treating or preventing in a mammal disease states or syndromes which are caused or associated with an estrogen deficiency or an excess of estrogen.
The present compounds have the ability to behave like estrogen agonists by lowering cholesterol and preventing bone loss. These compounds are useful for treating many maladies which result from estrogen excess or deficiency including osteoporosis, prostatic hypertrophy, male pattern baldness, ovarian cancer, infertility, breast cancer, endometrial cancer, cardiovascular disease, contraception, Alzheimer""s disease, cognitive decline and other CNS disorders, as well as certain cancers, including melanoma, prostrate cancer, cancers of the colon, CNS cancers, among others. Additionally, these compounds can be used for hormone replacement therapy in post-menopausal women or in other estrogen deficiency states where estrogen supplementation would be beneficial.
The compounds of this invention may also be used in methods of treatment for bone loss, which may result from an imbalance in an individuals formation of new bone tissues and the resorption of older tissues, leading to a net loss of bone. Such bone depletion results in a range of individuals, particularly in post-menopausal women, women who have undergone hysterectomy, those receiving or who have received extended corticosteroid therapies, those experiencing gonadal dysgenesis, and those suffering from Cushing""s syndrome. Special needs for bone replacement can also be addressed using these compounds in individuals with bone fractures, defective bone structures, and those receiving bone-related surgeries and/or the implantation of prosthesis. In addition to those problems described above, these compounds can be used in treatments for osteoarthritis, hypocalcemia, hypercalcemia, Paget""s disease, osteomalacia, osteohalisteresis, multiple myeloma and other forms of cancer having deleterious effects on bone tissues. Methods of treating the maladies listed herein are understood to comprise administering to an individual in need of such treatment a pharmaceutically effective amount of one or more of the compounds of this invention or a pharmaceutically acceptable salt thereof. This invention also includes pharmaceutical compositions utilizing one or more of the present compounds, and/or the pharmaceutically acceptable salts thereof, along with one or more pharmaceutically acceptable carriers, excipients, etc.
It is understood that the dosage, regimen and mode of administration of these compounds will vary according to the malady and the individual being treated and will be subject to the judgement of the medical practitioner involved. It is preferred that the administration of one or more of the compounds herein begin at a low dose and be increased until the desired effects are achieved.
Effective administration of these compounds may be given at an effective dose of from about 0.1 mg/day to about 1,000 mg/day. Preferably, administration will be from about 10 mg/day to about 600 mg/day in a single dose or in two or more divided doses. Such doses may be administered in any manner useful in directing the active compounds herein to the recipient""s bloodstream, including orally, parenterally (including intravenous, intraperitoneal and subcutaneous injections), and transdermally. For the purposes of this disclosure, transdermal administrations are understood to include all administrations across the surface of the body and the inner linings of bodily passages including epithelial and mucosal tissues. Such administrations may be carried out using the present compounds, or pharmaceutically acceptable salts thereof, in lotions, creams, foams, patches, suspensions, solutions, and suppositories (rectal and vaginal).
Oral formulations containing the active compounds of this invention may comprise any conventionally used oral forms, including tablets, capsules, buccal forms, troches, lozenges and oral liquids, suspensions or solutions. Capsules may contain mixtures of the active compound(s) with inert fillers and/or diluents such as the pharmaceutically acceptable starches (e.g. corn, potato or tapioca starch), sugars, artificial sweetening agents, powdered celluloses, such as crystalline and microcrystalline celluloses, flours, gelatins, gums, etc. Useful tablet formulations may be made by conventional compression, wet granulation or dry granulation methods and utilize pharmaceutically acceptable diluents, binding agents, lubricants, disintegrants, suspending or stabilizing agents, including, but not limited to, magnesium stearate, stearic acid, talc, sodium lauryl sulfate, microcrystalline cellulose, carboxymethylcellulose calcium, polyvinylpyrrolidone, gelatin, alginic acid, acacia gum, , xanthan gum, sodium citrate, complex silicates, calcium carbonate, glycine, dextrin, sucrose, sorbitol, dicalcium phosphate, calcium sulfate, lactose, kaolin, mannitol, sodium chloride, talc, dry starches and powdered sugar. Oral formulations herein may utilize standard delay or time release formulations to alter the absorption of the active compound(s). Suppository formulations may be made from traditional materials, including cocoa butter, with or without the addition of waxes to alter the suppository""s melting point, and glycerin. Water soluble suppository bases, such as polyethylene glycols of various molecular weights, may also be used.
Compounds of this invention may be prepared by methods known in the art. For instance, the starting or core indoline can be prepared by the general methods of Schemes 1 and 2, below. 
The synthesis of the compounds in this invention may be accomplished by deprotonation then alkylation of the core template 1 or 6 using the sodium salt of hexamethyldisilyl amide and the desired side chain. (Schemes 1 and 2) 